Crops face problems of agronomic management and diseases, increasing costs and environmental contamination. Ascorbic acid (AA) is an antioxidant compound which induces plant growth-responses to cope with stress. The effect of AA on chrisantemum (Dendranthema grandiflora Tzvelev) cv. Polaris under greenhouse condition was evaluated. Plants were sprayed twice a week with 0, 3.4 and 6.8 mM of AA from 30 days after transplant up to harvest time (100 days after transplant). AA significantly increased shoot length, dry weight, number of floral buds and stems per plant in contrast with control, being 6.8 mM the best treatment which enhanced biomass. AA significantly enhanced protein content (36 %), total photosynthetic pigments (75 %) and peroxidase activity (33 %) respecting the control, these responses were associated to the evaluated growth parameters.